The mechanisms that balance food intake and energy expenditure determine who will be obese and who will be lean. One of the molecules that regulates energy balance in the mouse is the obese (ob) gene. Mutation of ob results in profound obesity and type II diabetes as part of a syndrome that resembles morbid obesity in humans. The ob gene product may function as part of a signalling pathway from adipose tissue that acts to regulate the size of the body fat depot.

Positional cloning of the mouse obese gene and its human homologue

The European Working Group on Sarcopenia in Older People (EWGSOP) developed a practical clinical definition and consensus diagnostic criteria for age-related sarcopenia. EWGSOP included representatives from four participant organisations, i.e. the European Geriatric Medicine Society, the European Society for Clinical Nutrition and Metabolism, the International Association of Gerontology and Geriatrics-European Region and the International Association of Nutrition and Aging. These organisations endorsed the findings in the final document. The group met and addressed the following questions, using the medical literature to build evidence-based answers: (i) What is sarcopenia? (ii) What parameters define sarcopenia? (iii) What variables reflect these parameters, and what measurement tools and cut-off points can be used? (iv) How does sarcopenia relate to cachexia, frailty and sarcopenic obesity? For the diagnosis of sarcopenia, EWGSOP recommends using the presence of both low muscle mass + low muscle function (strength or performance). EWGSOP variously applies these characteristics to further define conceptual stages as 'presarcopenia', 'sarcopenia' and 'severe sarcopenia'. EWGSOP reviewed a wide range of tools that can be used to measure the specific variables of muscle mass, muscle strength and physical performance. Our paper summarises currently available data defining sarcopenia cut-off points by age and gender; suggests an algorithm for sarcopenia case finding in older individuals based on measurements of gait speed, grip strength and muscle mass; and presents a list of suggested primary and secondary outcome domains for research. Once an operational definition of sarcopenia is adopted and included in the mainstream of comprehensive geriatric assessment, the next steps are to define the natural course of sarcopenia and to develop and define effective treatment.

/pdf/sarcopenia-european-consensus-on-definition-and-diagnosis-2axty2moc3.pdf

Sarcopenia: European consensus on definition and diagnosis Report of the European Working Group on Sarcopenia in Older People

Summary: In 1995 the American College of Sports Medicine and the Centers for Disease Control and Prevention published national guidelines on Physical Activity and Public Health. The Committee on Exercise and Cardiac Rehabilitation of the American Heart Association endorsed and supported these recommendations. The purpose of the present report is to update and clarify the 1995 recommendations on the types and amounts of physical activity needed by healthy adults to improve and maintain health. Development of this document was by an expert panel of scientists, including physicians, epidemiologists, exercise scientists, and public health specialists. This panel reviewed advances in pertinent physiologic, epidemiologic, and clinical scientific data, including primary research articles and reviews published since the original recommendation was issued in 1995. Issues considered by the panel included new scientific evidence relating physical activity to health, physical activity recommendations by various organizations in the interim, and communications issues. Key points related to updating the physical activity recommendation were outlined and writing groups were formed. A draft manuscript was prepared and circulated for review to the expert panel as well as to outside experts. Comments were integrated into the final recommendation.

Primary Recommendation: To promote and maintain health, all healthy adults aged 18 to 65 yr need moderate-intensity aerobic (endurance) physical activity for a minimum of 30 min on five days each week or vigorous-intensity aerobic physical activity for a minimum of 20 min on three days each week. [I (A)] Combinations of moderate- and vigorous-intensity activity can be performed to meet this recommendation. [IIa (B)] For example, a person can meet the recommendation by walking briskly for 30 min twice during the week and then jogging for 20 min on two other days. Moderate-intensity aerobic activity, which is generally equivalent to a brisk walk and noticeably accelerates the heart rate, can be accumulated toward the 30-min minimum by performing bouts each lasting 10 or more minutes. [I (B)] Vigorous-intensity activity is exemplified by jogging, and causes rapid breathing and a substantial increase in heart rate. In addition, every adult should perform activities that maintain or increase muscular strength and endurance a minimum of two days each week. [IIa (A)] Because of the dose-response relation between physical activity and health, persons who wish to further improve their personal fitness, reduce their risk for chronic diseases and disabilities or prevent unhealthy weight gain may benefit by exceeding the minimum recommended amounts of physical activity. [I (A)]

Physical activity and public health: updated recommendation for adults from the American College of Sports Medicine and the American Heart Association.

Ten per cent of the world’s school-aged children are estimated to be carrying excess body fat (Fig. 1), with an increased risk for developing chronic disease. Of these overweight children, a quarter are obese, with a significant likelihood of some having multiple risk factors for type 2 diabetes, heart disease and a variety of other co-morbidities before or during early adulthood. The prevalence of overweight is dramatically higher in economically developed regions, but is rising significantly in most parts of the world. In many countries the problem of childhood obesity is worsening at a dramatic rate. Surveys during the 1990s show that in Brazil and the USA, an additional 0.5% of the entire child population became overweight each year. In Canada, Australia and parts of Europe the rates were higher, with an additional 1% of all children becoming overweight each year. The burden upon the health services cannot yet be estimated. Although childhood obesity brings a number of additional problems in its train – hyperinsulinaemia, poor glucose tolerance and a raised risk of type 2 diabetes, hypertension, sleep apnoea, social exclusion and depression – the greatest health problems will be seen in the next generation of adults as the present childhood obesity epidemic passes through to adulthood. Greatly increased rates of heart disease, diabetes, certain cancers, gall bladder disease, osteoarthritis, endocrine disorders and other obesityrelated conditions will be found in young adult populations, and their need for medical treatment may last for their remaining life-times. The costs to the health services, the losses to society and the burdens carried by the individuals involved will be great. The present report has been written to focus attention on the issue and to urge policy-makers to consider taking action before it is too late. Specifically, the report:

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1467-789X.2004.00133.x

Obesity in children and young people: a crisis in public health.

Targeted disruption of the melanocortin-4 receptor results in obesity in mice

Effects of Secret in and Cholecystokinin-Pancreozymin on Pancreatic Juice and Insulin Secretion of Goats

A water-filled balloon system was used to study gastric hunger contractions in normal rats. Fasted rats have active hunger contractions alternating with periods of quiescence. The contractions occur at a rate of one or two per minute for 10–15 minutes followed by a quiescent period of 5–10 minutes. Exposure to cold (5°C) and heat (32° and 40°C) inhibited gastric hunger contractions in fasted rats. Intravenous administration of 75 µg glucagon or i.v. injection of 50 µg epinephrine and norepinephrine also inhibited gastric hunger contractions. Cessation of the gastric motility also occurred when 100 µg glucagon or 50 µg epinephrine were given to fed animals pretreated with 2 u insulin. It was found that changes in carbohydrate utilization induced by glucagon preceded the gastric phenomena.

http://ajplegacy.physiology.org/content/ajplegacy/197/2/269.full.pdf

Relation of metabolic events to gastric contractions in the rat.

Yellow mice fed ad libitum exhibit a greater rate of lipogenesis and cholesterogenesis than their controls. Females show a fatty acid content in the liver and in extrahepatic tissues which is twice as high as the males. Unlike the males, they are hypercholesterolemic and also show an elevated rate of lipogenesis after an 18-hour fast.

Jean Mayer

Papers

Effects of Secret in and Cholecystokinin-Pancreozymin on Pancreatic Juice and Insulin Secretion of Goats

Relation of metabolic events to gastric contractions in the rat.

Fat metabolism in experimental obesities. IX. Lipogenesis and cholesterogenesis in yellow obese mice

Obesity: Physiologic Considerations

Induction of Hypothalamic Aphagia and Adipsia in Goats